Once you have decided on a number, test to see if it exists by typing it into the search box. If it exists, you can add the part to your cart. For additional assistance contact our tech team at 888-800-9629.

Example: R5671A-10 has a heat range of 10. A colder plug would be # R5671A-11 (heat range 11), a hotter plug would be # R5671A-9 (heat range 9).

Some NGK Racing Plugs are also available in half heat ranges. These are displayed as a 2 or 3 digit number after the hyphen. For example, R6120-85 has a 8.5 heat range and R6120-105 has a 10.5 heat range.

For additional assistance contact NGK customer service at 877-473-6767.